Garments, including pant-like absorbent garments, medical garments, and other products, are commonly made with an elastic containment feature adjacent at least one of the garment openings. A pant-like garment, for instance, may have an elastic containment feature adjacent the waist opening, each of the two leg openings, or all three of the openings. The elastic containment features are intended to fit snugly around a wearer""s body to serve as gaskets, which prevent or reduce leakage of waste materials from inside the garment. Elastic containment features have also been employed in leg flaps that provide further leakage protection in pant-like garments, and in other auxiliary gasketing applications.
Many conventional elastic containment features are made of a folded web with a high propensity to ruffle and buckle during use. As a result of ruffling, the gasketing and containment characteristics around the openings in the garment are compromised and leakage occurs.
Thus, there is a need or desire for an elastic laminate for use as an elastic containment feature in garments which provides a consistent gasket to reduce ruffling and prevent or reduce leakage.
There is also a need or desire for an elastic laminate for use in an elastic containment feature which provides for a more attractive fit around the openings of the garment, for example the waist and leg openings.
In response to the discussed difficulties and problems encountered in the prior art, a stretch edge elastic laminate (xe2x80x9cSEELxe2x80x9d), has been discovered. The SEEL has at least one elastic filament layer having a plurality of elastic filaments, desirably thermoplastic filaments, aligned in a machine direction and forming an elastic zone or region and at least one gasket zone or region defined by a stretch edge aligned in the machine direction. The elastic filament layer is positioned adjacent to one or two facing layers. An elastic film or plug is located adjacent to the facing layer(s) at one or both side edges of the laminate. The stretch edge is defined by the elastic film or plug and the facing layer(s) at one or both edges.
Suitable polymer or polymer blends used to prepare the elastic filaments and the elastic film or plug include olefin polymers, such as an olefinic copolymer of polyethylene. More specifically, other suitable polymers include diblock, triblock, tetrablock or other multi-block elastomeric copolymers such as olefinic copolymers. The elastic filaments and the elastic film or plug may also contain blends of elastic and inelastic polymers, or of two or more elastic polymers, provided that the blend exhibits elastic properties.
The elastic filaments may be made of a first elastomer or elastomer blend, and the elastic film or plug may be made of the same or a different elastomer or elastomer blend, having different tensile properties than the first elastomer or elastomer blend. In another embodiment, the elastic filaments may be a first elastomer and the elastic film or plug may be an elastomer blend having a different percentage amount of the first elastomer, with an added non-elastic component, making the modulus of the second elastomer blend greater than the modulus of the first elastomer.
In another embodiment, the elastic film or plug may be a blend of elastomers, for example KRATON(copyright) styrene-ethylene/propylene rubber and a polyethylene elastomer, having a modulus and/or basis weight (and, thus, tension) greater than a modulus and/or basis weight of a first elastomer used to form elastic filaments. The polyethylene is added to increase the modulus for the elastomeric film or plug.
Desirably, a first elastic film or plug is positioned along a first lateral edge portion of the SEEL and substantially aligned in the machine direction and a second elastic film or plug is positioned at an opposing second edge portion of the SEEL and substantially aligned in the machine direction. The elastic filaments are positioned within the elastic layer, between the first elastic film or plug and the second elastic film or plug. Desirably, each elastic film or plug has a width of about 0.078 inch to about 0.236 inch, more desirably about 0.118 inch.
The polymer or polymer blend used to make the elastic filaments may have a different tension (i.e., exhibits different retractive force when stretched) than the polymer or polymer blend used to make the elastic film or plug. Thus, the elastic zone may have a first tension and the gasket zone may have a second tension different from the first tension. Desirably, but not necessarily, the second tension is equal to or greater than the first tension.
A first facing material is bonded to a first side of the elastic layer and an opposing second facing material can be bonded to a second side of the elastic filament layer. Each of the facing materials desirably is a nonwoven web, formed using conventional web forming processes. The first facing material and the second facing material may be made of the same or similar material or different material. Additionally, a barrier film, desirably a polymer film such as a polyethylene film, can be positioned between the elastic layer and the first facing material and/or the second facing material.
The SEEL in accordance with this invention may be made or produced, for example using a continuous vertical filament laminate (xe2x80x9cVFLxe2x80x9d) method. Other suitable processes, for example a continuous filament spunbond laminate (xe2x80x9cCFSBLxe2x80x9d) process, may be used to produce the SEEL material in accordance with this invention. Molten elastomeric material may be extruded from a first spin plate region as a plurality of elastomeric filaments. Similarly, a wide elastic member may be extruded from a second spin plate region through a rectangular slot. The resulting elastic layer may have a higher elastic tension and/or lower stretch in the gasket zone, due to the wide elastic member, than in the elastic zone, which contains the elastic filaments. After extruding, the elastic filaments and the wide elastic member are quenched and solidified and then stretched or elongated. The elastic filaments and the wide elastic member can be stretched by about 100% to about 800% of an initial length, desirably by about 200% to about 700% of an initial length.
Before or after the elastic filaments and the wide elastic member are stretched, the elastic layer is laminated to the first facing material and/or a second facing material. The laminate material is then bonded and is relaxed and/or retracted to produce the SEEL. The laminate material can then be slit or cut through a general centerline of each wide elastic member to form a corresponding elastic film or plug positioned along each lateral edge portion or region of the SEEL. The wide elastic member can be slit or cut using any conventional slitting or cutting means known to those having ordinary skill in the art. As a result of the slitting of each wide elastic member, the SEEL will have a continuous gasket zone, defined by the elastic film or plug, positioned along each lateral edge portion or region. Alternatively, if the wide elastic member is positioned at the edge(s) of the laminate prior to cutting, the laminate need not be cut to form the stretch edge.
The invention encompasses various types of garments or absorbent articles in which a gasket zone is present in the vicinity of any one or more garment openings. Depending on the garment, gasket zones may encircle an entire garment opening or just a portion of the garment opening. Types of garments on which this invention can be used include personal care garments, such as diapers, training pants, absorbent underpants, adult incontinence products, certain feminine hygiene articles, and swim wear, as well as in medical garments.
With the foregoing in mind, it is a feature and advantage of the invention to provide a stretch edge elastic laminate having a continuous gasket zone with elastic properties positioned along at least one lateral edge region of the laminate material.
It is also a feature and advantage of the invention to provide a stretch edge elastic laminate having an elastic zone and a gasket zone with different tension and/or elastic properties.